Hello and welcome.
So before jumping into console and just running through the simulation, let's go back and learn a little
bit of theory.
What is actually at the charging of a capacitor?
Don't worry.
I will not take too much time to explaining all the basics, but I'll just go through the very basics
which is needed so we know that a capacitor is present or something like this where let's say when the
capacitor is charged, one side will be positively charged, something like this, and the other side
for a battery powered capacitor will be negative.
So positive and negative, which will form a potential gap and then the energy stored in this fashion.
This is how the capacitor actually stored charge.
So for, you know, starting the charging up a capacitor, let us consider a very basic circuit.
So we have our battery and then we have a resistance connect to it.
Let's say we have a switch and then we have a capacitor and our circuit is closed.
So we have to here.
This is our this is capacitor C, so when the circuit will be closed, the potential across the receiver
will be we are and the potential across the capacitor will be v.c.
So when a battery is connected to a series Destra and Capacitor, the initial current is high as the
battery transport charge from one plate of the capacitor to the other.
The charging current asymptomatically approaches zero as the capacitor and becomes charged up to the
battery voltage.
Charging the capacitor restores energy in the electric field between the capacitor blades and the rate
of charging typically describe the term.
Uh, that is the time constraint so far.
This circuit, the time constant is our C, so this term is important for charging of a capacitor.
Now let us, uh, just write it down in very basic form.
So VB will be.
We are plus v.c.
This is very clear, the potential difference, uh, across the register and the potential difference
across the capacitor.
So which can be simplified as I r that is current time resistance plus Q by C that is the charge by
the capacitance which is the voltage.
Right.
So if you see at time DeCola Desierto, that is when the circuit is open, uh, so the charge will be
zero, the potential across the capacitor will be zero and the current will be Vehbi by R right.
Initially when it is just starting.
So at the very last time let's say DeCota T1, which is very large timelessly infinity, then the charge
will be three times will be right, because at very last time the charge will fail up until it gets
to equal to the potential difference across the source and v.c will tends to be it will be slightly
less than VB, but still close to Fibi and the current flow will be zero Y because the current will
flow until the capacitor is fully charged.
Right.
So as soon as the capacitor filters, the current flow will be zero.
So now let's try to look at how the plot actually looks.
So let's do a thing.
Let's draw the curve.
So I'll draw this part with black and then the other part with pink.
And what we will do this is the charging current and this is the charge on capacitor.
OK, and let's say this is the time.
This is the time this is the to zero now, as soon as you turn on the switch in the circuit, so as
soon as it's turned on the switch in the circuit, what will happen is the current will start from a
maximum value and then it will slowly die down and saturate to zero.
And similarly, the charge in the capacitor will increase and it will saturate to value.
This saturation value is three times Vehbi, right?
We already discussed this here.
So the saturation charge will be three times the VB and the initial current this is the I-Max, which
is at the starting phase will be Vehbi by R.
So this is V, B by R, right.
This is one very basic theory in physics.
So what we will do is let's jump back to commercial in our next lecture and then we'll try to set up
the circuit and then we'll verify all these theories together.
Right.
So thanks for watching and we'll be back in our next lecture.